FIG. 18 is a flowchart of a window display system using a conventional method. In the conventional system, firstly a window is created or obtained (S101), and a structure of the window associated with an event processing program is assigned to the created window (S102). Next, the window is drawn on a display (S103), and finally the window waits for occurrence of events (S104). Then, when an event, such as key inputting or mouse operation, occurs (S105a), the event is detected by a window management unit (S105b), and the event processing program is executed (S106). When the event processing program completes the executing, the window merely waits again for events.
Note that the “structure of a window (window structure)” is a set of display elements (data) to be displayed on the window. The expression of “assigning a window structure to a window” means associating the window structure with the window to be drawn. The “drawing a window” means displaying the window together with the window structure which is associated with the window on a display.
As far as such a processing method of the window display system is used, a new different window needs to be display in order to display a different window structure on the window. Therefore, in a general multi-window display system 110 as shown in FIG. 19, not only a main window 111 but also plural sub-windows 112 are opened, and these windows are displayed by overlapping one another or switching among them.
However, a window consumes a large amount of system resources, such as a memory. Therefore, a system having a large number of windows consumes more system resources, which is inefficient.
On the other hand, a single-window display system, such as JAVA™ APPLET, displays a window in a browser. However, APPLET displays only a single window, but cannot display various windows by switching them.
Furthermore, as disclosed, for example, Japanese Patent Application Laid-Open No. 2003-186593, a method of switching display contents in plural windows has been known.
However, this conventional reference discloses that a window is drawn by switching plural windows, but window structures are not able to be switched to be displayed within a single window.